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Is it possible to change 300tdi piston rings with engine in?

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I have a 300tdi 110 defender (1995) that has done 235,000 miles and I am now experiencing severe cold starting and pour performance problems. I’m guessing it is either the head gasket or the rings (there is a new high pitch rattle occasionally). Hopefully a compression test will help me diagnose the problem. Changed glow plugs last night (forever hopefull!!!)

My question:Is it possible to undo the big ends and push the pistons and con rod assembly up from underneath when the head is off without removing the engine or any steering? Not really been under the 300tdi much but I am sure I did this on a series 3 years ago.

Many thanks in advance.


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I had my head 'done' changed the rings and honed the bores (down Rover) at 100k miles. The bores were a bit stuffed due to running a K&N filter (don't get me started on that one). My engine now has 150k miles and is going well.

But at your mileage I would think that the engine needs a complete overhaul, including a rebore, only changing the rings might be a waste of time and money. It's up to you, of course. Maybe take the head off and see what the bore wear is like.

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  • 2 weeks later...

Thanks for that, your dead right. Half the reason to go straight for the rings was to se the general condition of the engine as well. Should have done a compression test first as the bores, rings and big ends were fine. The piston rings were second oversize and I would say it had a short engine not that long ago. Still new rings and bearings didn't hurt and the rockers were shot to bits. Unfortunatley I still have really bad white smoke on start up and now a very serious vibration when under load; sounded like pinking to start but now feels like a vibration (almost like a UJ has gone).

Can diesels pink like a petrol; the only thing left that I havent looked at is the injector pump as I have also now replaced the injectors (bargain on ebay).

Never done anything with diesels before (lots of v8 and series though); is it possible to check the injector pump timing without the specialist tools for lining up the flywheel and injector pump? Any other ideas what it might be; seems a shame to admit defeat and take it in to the garage (not to mention the labour)!

Many thanks in advance


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I have stripped a 300TDi engine right down to the bare block/timing gear, with the engine still attached to the gearbox.

Remove the head as described here:-


Then it's just a matter of draining the engine oil, removing the sump, undoing the big-end cap bolts, and pushing the piston/con rod assembly out the top of the bores.

Look also through this thread:-



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